Making a Seamless Scale Material Part II

In part I of this tutorial, I went over my process for creating a tile- able texture mask using photoshop and illustrator. We ended with how different applied effects done in photoshop could alter the basic outcome a sculpted tile inside of Zbrush.

In this lesson, I want to go over how to apply that texture in Zbrush and then further refine it using Zbrush's robust sculpting tools and a combination of masking techniques. While I will personally be working with a mask that I did indeed create in photoshop, this process can be easily applied and used without having a mask at all.  We will go over some helpful tips and hints that can help us keep our texture seamless and furthermore, expedite the sculpting process so that we can get great results with less effort. 

For this tutorial, you will need the following programs : Zbrush.

If you created a seamless pattern from the first part of this document, then be sure to have that file as well! 

Setting up your seamless pattern overview : 

If you followed the first part of the tutorial, then you will already have a prepared document to use. Before getting started with this part of my process however, I wanted to go over a little more in depth about how to save out my seamless pattern mask. 

1.) Your seamless pattern should be at least 1024 x 1024 ( 1k square) or higher.  In the last tutorial, I set up my file so that it was a 1K square, however, making it 2K or 4K, could have its benefits. If you are looking for some very refined, precise and clean detail, right off the bat, then I would recommend creating your pattern in a 4k document ( 4096 x 4096) .

2.) Your seamless pattern should be saved out as a JPEG. If not, Zbrush won't be able to load the mask as a displacement texture. You will recieve an error log that says something along the lines of :  "Displacement and Bump Mapping requires Texture Map".  This occurs if you save out your files a a PSD or a PNG and then try to import it under your displacement texture property. 

Setting up your Zbrush Scene: 

1.) Open Zbrush and resize your canvas to a square. ( Document> Document Size> resize ).  You can set it to any size you want. The canvas size will reflect the ultimate size of your alpha once it is exported. remember, you can always change your document size at anytime.   I kept my canvas size relative to the size of my pattern file and set it to 1024 px x 1024 px.

2.) Choose the Plane 3D from your tool slot and drag it onto your new canvas. Make Polymesh 3D in order to make it editable,

3.)  Subdivide your new Plane. Turn off the Sub Divide Smooth Modifier (smt) inside of your geometry panel, before dividing your mesh. You can choose to click the divide button, or simply use the shortcut ( cntrl + d ). You should divide your mesh so it has at least six levels. You can choose to subdivide your mesh later should you decide you need more detail, 

Applying your Mask as a displacement: 

Now it is time to pull out your seemless texture created in Part 1..  If you if you did not follow part 1, you can skip down to Sculpting techniques . 

There are many ways to approach sculpting your scales. If you added filters to your photoshop file, you may want to apply your texture as a displacement map and then continue to refine it. If not, however, you may choose to just load in your pattern as a mask that you can then use to manipulate your mesh into a look you desire. 

Loading your pattern as a Displacement : 

1.)  First you need to create a new texture. To do this, go to tools> Texture map > new Texture. You will know if this is done successfully when the grey box in the Texture map pallete becomes white.  ( You must have a texture map in order to load in your pattern as a displacement alpha, otherwise, Zbrush will not be able to apply it.) 

2.) Next, you need to apply your pattern as an alpha for displacement. Go to tools> displacement map > Viewing box> import. A popup will ask you to choose a file. Select your pattern. 

! ) Initially, you wont see a change on the actual plane, but you will know that the displacement map is loaded when you see your pattern now loaded in the viewing box. At this point, in order for displacement to take effect, you need to play with the intensity slider. 

***** The designated intensity is solely dependent on the scale of your polymesh and of course your preference and overall goal. There is no exact science. Just play with it until you find something you like. :) 

3.) Finally, once you find something you like, you can "Apply Displacement" ( tools> displacement map> apply displacement. ) The intensity preview of your seemless pattern will be baked as a sculpt onto your new plane. 

Below is what my polyplane looks like after applying my dsplacement map : 

While my scales look pretty good, they could use some refining to make them look more defined. 

Sulpting Techniques: 

Now that we have created a nice clean "blueprint" so to speak, lets set up our brush so that we can further refine our patterning and keep tiling uniform. 

1.) Set up your brushes for tiling. 

When sculpting scales, there are two brushes that I use almost exculsively : Dam Standard , and Clay buildup. 

Dam Standard : Dam Standard allows for us to define our creases and edges. I also invert this brush when I really need to stregthen the silohuette of a detailed area. 

Clay Buildup: for details like scales, this is the best brush ever. The clay buildup brush allows to you really pile up the "bulge on scales by evening out the lowest parts of the mesh first and building up . 

In each of these brushes, we want to make sure we tweak some settings so that we can contine to build up detail on our tiles without worrying about seams in the displacement map showing through. 

Step 1: Inside each of the brushes you intend to use, turn on Wrap Mode : Brush>Curve> WrapMode =1.

The image above illustrates what Wrap-mode does. It essentially continues your stroke onto the other side of the plane, making patterning seamless. 

Once your burshes are set, you can start dculpting. If you do not have an alpha -applied-displacement, then you may want to consider increasing your wrap mode. This will in turn increase the increments at which it is set so that you can go ahead and draw uniforn scales. 

Using An alpha blue-print to your advantage : 

If you are anything like me, you'll want to be able to create the best sculpt you can in as little amount of time as possible. To help you achieve a nice and clean sculpt with defined edges and clean lines, applying your black and white alpha as a mask can help. 

First, go to the alpha picker and select the map you want to use as a mask.

Then go to : Tools > Masking> Mask By Alpha. By turning this on, a mask will appear over your sculpt. By sculting with the mask and inverting it, you can further control your sculpting process. 

Capturing your Alpha + Checking for Seams :

Once you find yourself in a good spot with your sculpt, it is time to extract the new Alpha. This new Alpha can help you in Zbush by allowing you to take advantage of tiling over your sculpt or projecting details over your objects.  You can use it as an alpha in your burshes and essentially wipe out hours of detailing by hand. If you plan on using it as an aid in your shader, you can apply your new alpha as a bump to create nice and detailed shaders in renderers like Mental Ray and Vray. 

To capture your alpha you want to make sure your canvas is set to a perfect square. Frame your plane in the canvas by hitting "F". if your plane is not flat, Shift +drag to flatten it to the nearest orthographic view. Additionally, since we are capturing this orthgraphically, make sure Perspective is OFF.  

 When your plane is center go to : Alpha> GrabDoc

When you click this, a new alpha mask is created. You can see it now within your alpha panel.  

Once you have done this, with your grabDoc currently selected in the Alpha viewer, you can Export.  8 times out of ten, your Doc will be tilable. In my case, my inflated sculpt warped the edges, creating seams. Before Grabbing your doc, check to make sure that it is tilable. 

Checking for Seams : 

 Checking to make sure that your doc is tilable is easy within Zbrush. To do this, you simply need to Go into 2.5D mode and use the Tilda (~) key to drag your doc through the ViewPort. By doing this, you can check if it has seams. 

Note : 

2.5 D mode means that your "Edit" Mode is Toggled off and your "Draw Mode" is Toggled on. 

My Image with a seams and my image without seams after using Tilda tiling.

 To remove the seams, I simply zoomed in on my Plane, maintaining its center position. This helps to ensure that the "target space is still tilable. Since I had off set every other row, I had to take that into consideration and zoomed in until to rows on the edges matched. Vertically, there is no offset so the right and left sides matched up. 

When you are satisfied that your texture does indeed tile, Capture the doc again and export it out. 

Now you have a "height map" otherwise known as a "bump map" that you can either use within Zbrush with Projection master and other tools, or you can use it when building materials to create seamless scales at render time! 

Part III: Building a Scales Material Using Vray inside of Maya.  >>>